Study finds no solvent vapor in most Algona homes tested

BELLEVUE – Recent indoor air tests in northern Algona homes show no cause for
health concerns. That’s according to a study directed by the Washington State
Department of Ecology (Ecology) and an
assessment
of the study findings issued by the Washington State Department of Health at
Ecology’s request.

The indoor air study is part of an ongoing
investigation of groundwater contaminated by past releases of solvent
chemicals on property owned by The Boeing Company (Boeing) in Auburn. Ecology
oversees the investigation conducted and paid for by Boeing.

Ecology ordered the indoor air quality study based on results of
groundwater tests
conducted in the northern part of the City of Algona in April 2013. Those tests
showed low concentrations of contamination in an area just west of Chicago
Avenue, between Boundary Boulevard and Ninth Avenue North. There are 24 homes in
this part of the groundwater study area.

The City of Algona has aided the study and the overall investigation with
arrangements for sampling on city property and other support.

Investigators are seeking to confirm the location and determine the potential
impacts of contamination in the groundwater, primarily
trichloroethene (TCE), and other chemicals such as vinyl chloride (VC),
which forms when TCE breaks down.

Indoor air tests a precaution

TCE and VC in shallow groundwater can release vapors into the soil. These
vapors can enter a building through a crawlspace or cracks and other openings in
a foundation. This is called vapor intrusion. In high enough concentrations over
time, exposure can put people at risk for cancer and other illnesses.

The concentrations detected in the groundwater were not expected to threaten
the health of people in these homes. The air sampling confirmed this.

The owners of 14 of the 24 homes agreed to the testing in the summer and fall
of 2013. Nine homes were clear of the chemicals of concern (TCE and breakdown
products). Five homes had one or more low-level detections of TCE. Three of
these five homes had TCE only in the living space; one home had it only in the
crawlspace; and one had it in both. The detections do not indicate that vapor
intrusion from groundwater contamination is the likely source. Other possible
sources of chemicals found in indoor air include common household products, such
as paints, solvents and cleaning products.

According to the state health department evaluation, the results indicate
that breathing the chemicals at levels found during the sampling is not expected
to cause harmful health effects. The department recommends continued indoor air
monitoring in the study area.

Sampling is voluntary and free of charge

Ecology has directed Boeing to conduct a second phase of the indoor air study
in Algona this winter when the groundwater is higher. The company’s
environmental contractor, Landau Associates, has contacted homeowners and
residents in the same study area to request their participation in the voluntary
sampling study. The sampling is available free of charge to all 24 homes in the
study area.

Related studies

Ecology continues to direct other parts of the investigation:

Surface water study: The groundwater in Algona can be very high in
the winter and can mix with rainwater when it enters low-lying areas, such as
yards and roadside ditches. This study will help determine whether groundwater
contaminants may be present in this surface water, and, if so, at what
concentrations. Boeing’s contractor, Landau Associates, has:

Contacted owners and occupants of 32 homes and undeveloped
lots to request permission to collect water samples from ponds
that form on their property in rainy weather. These are located
in the northeastern residential area above or near areas where
the April 2013 groundwater sampling detected some contamination.

Upcoming investigation projects include drilling additional groundwater
monitoring wells in northeastern Algona. The new monitoring wells will allow for
continued sampling of the shallow and deeper portions of groundwater to track
the contaminant concentrations over time.

Drinking water is safe

The groundwater contamination does not affect the municipal drinking water
supply in Algona and Auburn. This is because the supply wells in Auburn are
located safe distances away from the contamination.